Evidence for Granulation and Oscillations in Procyon from Photometry with the WIRE satellite
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چکیده
We report evidence for the granulation signal in the star Procyon A, based on two photometric time series from the star tracker on the WIRE satellite. The power spectra show evidence of excess power around 1mHz, consistent with the detection of p-modes reported from radial velocity measurements. We see a significant increase in the noise level below 3mHz, which we interpret as the granulation signal. We have made a large set of numerical simulations to constrain the amplitude and timescale of the granulation signal and the amplitude of the oscillations. We find that the timescale for granulation is Γgran = 750±200 s, the
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تاریخ انتشار 2005